This patent document relates to a method and apparatus for generating textures for display.
Previous texture generating techniques include procedural texture and solid texture techniques. Procedural texture is a technique for generating texture by a function or a combination of several functions. This technique is described in Perlin""s articles: xe2x80x9cAn Image Synthesizer,xe2x80x9d Computer Graphics, Vol.19, No.3, pp.287-296, 1985; and xe2x80x9cHypertexture,xe2x80x9d Computer Graphics, Vol.23, No.3, pp.253-262, 1989. Solid texture is a technique for generating texture in three-dimensional space and enables representation of precut materials, such as lumber and marble, that are difficult to represent by two-dimensional texture. This technique is taught in Peachey""s article: xe2x80x9cSolid Texture of Complex Surfaces,xe2x80x9d Computer graphics, Vol.19, No.3, pp.279-286, 1985.
These techniques pose the problems of how to input data and how to preview object texture. As to how to input data, the conventional techniques dealt only with mathematical functions. The present invention enables line segments of texture to be defined not only by mathematical functions but also by use of an input device such as a tablet. As to how to preview object texture, conventional techniques have not addressed this matter. Inasmuch as the automatic generation of texture takes some amount of computation time, it is desirable to shorten the time between data input and texture output where texture is generated by trial and error. In these circumstances, substantial labor and time would be saved if an element of preview were introduced. The present invention facilitates this preview by use of line segments as texture feature variables.
The present invention includes enabling basic texture data to be input not only as mathematical functions but also by use of an input device, such as a tablet, and to provide a texture display technique capable of display textural features simply and previewing object texture easily.
In order to achieve the above-mentioned objects, this invention includes the steps of providing an evaluation value for each position within a predetermined two-dimensional coordinate range with respect to each position coordinate of a line segment, accumulating such evaluation values for each position within the two-dimensional coordinate range, providing two-dimensional graphics information on the basis of the accumulated evaluation values, and displaying graphics according to the two-dimensional graphics information. This separation of information about line segments from information about the method of modeling enables use of hand-written input of line segment information and also enables object texture to be previewed by use of skeleton information.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.